Manufacture of ethers



Aug. 31,- 1943. w.- A. CRAIG MANUFACTURE OF ETHER Filed Sept. 18, 1940 J'Zara e M 3% Ta rN m0 o M, mm

hols into the correspondingcthersa it 2,328,059llj1 n MANUFACTURE oi qn'rinnsff L Wallace Alexander Craig, Los 'Ang'eles'; Cal ilt, asl 'sig'nor to RichfieldOil Corporation, 1.65 An gele's,'t)alif., a corporation tofnelaware Application September 13, IQIQJSeriitl 5 ClaimsQ(Cl.266 14)"f"v H p I thetne ating zone either-continuously printer- This invention relatesto a process in the present inventionlI provide an of menufacturingethers and more particul-arly to aproc lessor; converting aliphatic mono-hydroxyflalcoe oved process of producing tethers in which an aliphatic alcohol, orymixtnre of: alcoholspin. vapor form; is

brought into contactwithasolutioneoi aheavy metal "at an elevatedvtempera-tureh .Bythe "term #heavy metal salts :I imean salts goi tzinjc, iconpeigcadmium, mercury, irozrp'hrornium, man'- gane'se, ahiminumQnicKel orcobalt. These salts maybe the chloride, bromide, sulfate, summer any or 'thewateror alcohol soluble saltsfiof the above :named metals of organic acids, such as 'ortltiersulfo acids derivedfrom the treatm'entct petmleumoils with sulfuric nacid. v t The processor the presentinvention possesses many advantagesover prior-processes Jot "prorluc-p ing ethers. The 'most'commonlyiusefl process" of jmethod employed forgthe manufactureofdiethyl ether inwhic'h freaction isicansed between :alcohol and sulfuric acid .and j the resultingproduct distilled." :This .prooess is particularly objectionable if the conversion is theprior art i the made in the presence of 1a hydrocarhmivlxoii.

wdersuch conditions*thesidereactions between the acid and the hydrocarbon Loi'l ttie qiiaiity of the finished material; y l n micarrying outimy invention I employ a Lumintained solution of a, heavy metaltsallttwirichiiap .pa'ently serves asa .dehydrating'icatalyst. My

is that two molecules rofgthe alcohol mew-one molecule of water and then combine tdllroducefone moleculegofetheri If thisiconccptlon is correct, theireactionlwhich takes place isfiasfollows: r v n 1 it when of atwo orimorealcoholsare .jected to the same treatment, the reactionsjare heavy metal salt serves as; [a i dehvdrating i went at the timet t ac onn endwremeve mo e water to rthus disturb l-the equilibrimn the tormation'otjether. r

Animpor mt a v ta 6: basementstion is that the purity of the aloohols from which r o o controlled. When the alcohol oialcohols ere ieet e isi-to .be -mad no m'ittentiy; Any objectionable reaction products appropriate means. As stated,-.:the alcohol need. notvbe free of tall impurities; Water mixed-therewith will not interfere wi-tl theoonversion; 'Ilhe presenlceof hydrocarbon oils does not'in-terefere with the conversion prOl/idedproperallomhnce is "madeto maintain; the concentrationof the t l ,10

saltat its .op-timum'point Other common impurities;- such as sulfur compounds, are] removed by the treatment, The temperature and pr-es sure atwhich the operation is carried outrnust be controlled in order tomaintainthg: concentration: of; the treating solution at a constan-twalue Due" to the: formation of water during the reac tiong, i'the" conditions must controlled: to drive i it out of the 'treater byflevaporation at snostan tiallylfthe isame rate atwbichtit is for-med. The

concentration of the treatingjsolotion may :be" rr'naintained within reasonable limits-p3 calculat .i-ng from the-vapor gpigessure of some -predete minedv'poncentration whatgthe temperature and pressure: ofthe ,systern shouldfloe in order to maintain the :desired partial pressure of water vapor. The operation then he carried out accordance with the calculated conditions'q;

Thefaccompanying drawing is :a. diagrammatic view {of one-form of apparatus :Suitable for 4,158 in practicing; the process.

In the drawing; the reference numeral l designates a. stoirageltanklfor theraloohol to be treated.

whe tank is provided with-ran outlet-controlled by :valve 2 azmtconneeted to a pump 3 capable of 1 delivering predetermined amounts of V liquid. The outlet of; the pump is'gconnected to a theater 4 which may be zprovided with an electric heat ing coil aim-other suitable heating means.- :The

? *heater is -in turn connected to o treating tower -6'which may beprovided with suitable heating means, herein shown asa heating coil El; V ,Snitable packing material 8 is arranged'withm the tower. A drain pipe Bis aconnected to the botbroughtintdcontact wrththe-somtion of a heavy I metal salt, theproducts ofreaction are, for the most part, discharged Iromfthe reaction zone as Y vaporand can be recovered. The solution of heavy metal salt may be circulated in and out of tomof the tower and is controlled by a. valve l3.

A pipe H. is connected to the 'tower'a'djacent the bottom and is gcontrolle'df hyj a valve j I2. This;

pipe may be employeddordelivering steam to the l3 is formed. "The'top'of thejsurge chamber is provided witha feed'opening l4 controlled by a valve l5: The heayy metal salt or other treating reagentis charged "into the towerthrough this opening. A pipe 16 is-connectedto the top of V the surge chamber :and; ionns .avapor line which extends into a coil arranged condenser l 11. 'I heflower end of the coil is connecteduto a discharge pipe ill. The condenser is' provided with an inlet I8 and an outlet IQ for water or other cooling fluid; In practicing theprocess, a suitable quantity of alcohol, for example isopropyl alcohol, is placed in tank i. The flow of alcohol is controlled by the valve 2 and by the, pump 3. The alcohol in liquid form; is delivered to. heater 1 which is maintained at a desired temperature. The alcohol is vaporized in the heater and is delivered into the bottom of the treating tower 6'.

The tower is charged with the desired treating reagent withthe level of theliquid in the treating tower almost up to the surge chamber 13. The temperature within the tower is controlled by the heating coil 7 or other suitable heating means. If desired steam may be introduced into the towerthrough pipe 22. The alcohol vapors pass up through the tower and are brought into intimate contact with the treating solution by the packing material 3. "-At the beginning of the process the vapors within the tower force a portion of the treating solution into the surge chamher but the-surge chamber is of such size that no over-flow into the vapor line 16 is permitted. Equilibrium is eventually established and the solution trickles down into tower B as rapidly as it is lifted into the surge chamber. The treated vapors, then pass through the delivery pipe iii into the condenser I1 and the cooled material is conveyed to suitable storage tanks through pipe 20.

, In this example a water solution of zinc chloride was usedas the treating reagent. Isopropyl alcohol delivered from tank I was vaporized in "the heater 4 and the vapors entered the treating tower at a temperature of 4g00 F; to 450? F.

The temperature fluctuated between 380 F. and 440 F. at thebottom of the tower, 300 F. and 345 F. adjacent the center of the tower,v and 325 F. and 400 adjacent thetop of the tower. The vapors passing through the system and recovered by-condensation consisted of water, an oil phaseand gas. I The gas consisted largely of propylene, a smaller amount of hydrogen, and lesser quantities of higher molecular weight maboiled betweenlOO F. and 537 F. A fraction of this material boiling up to 200 F. possessed excellent anti-knock-properties when blended with I gasoline and tested'in a'conventional test engine Table I Volume Volume I per cent per cent g g of A- in of sample nu er Va ue o blend in blend blend Sample 100 0 e 40. 3 e 90 45. 8 95.3 80 20? 51.5 96.3 70 58. 0 V 99. 3

In TableII are hown similar values of similar blends of isopropyl ether in A-e reference iuel. It will be notedthat the values obtained from the blends of Table I using the material resulting from the process herein described compare favorably withthe values of the blendemploying isopropyl ether. I

Greater than 100. I I 1 While the method described herein is well adapted tocarry out my invention, I do not wish to be limited to-the conditions herein set forth.

Other means of contacting the alcohol vapors with a maintained solution of aheavy metal salt may be used, such, for example, as a vessel provided with mechanical agitators. While I have described in my examples a method of treating,

in vapors phase, isopropyl alcohol with solutions I of zinc chloride, other aliphatic alcohols may be conditions.

, terials. Theoil phase had an ethereal odor and so treated; also solutions of other heavy metal salts may be employed to effect the desired dehydration, the choice depending upon specific The process is carried out at pressures preferably in excess of 35 pounds per square inch and not substantially in excess of 100 pounds per square-inch. The preferable pressures are from '35 to pounds per squarev inch.

This application is a continuation in part of application Serial No. 216,280, filed June 28, 1938.

I claim:

l. The method of manufacturing ethers which comprises vaporizing an aliphatic alcohol and delivering the alcohol vapors at a reactingv temperature and at a pressure between 35 and pounds per square inch into contact with a maintained solution of chloride of a heavy metal of the group consisting of zinc, copper, cadmium,

mercury, iron, chromium, manganese, aluminum,

nickel and cobalt.

2. The method of manufacturing ethers which comprises vaporizing an aliphatic alcohol, de-

livering the alcohol vapors at a temperature between 400 and 450 F. and at a pressure between 35 and '75 pounds persquare inch into contact with a maintained solution of a chloride of a heavy metal of the group consisting of zinc, copper, cadmium, mercury, iron, chromium, manganese, aluminum, nickel and cobalt, and maintaining a temperature of above 300 F. during contact of the vapor and the solution.

' 3. In the manufacture of an ether, the step which comprises contacting vapor of an aliphatic alcohol at a temperatureabove 300. F. and at a pressure between 35 and 75 pounds per square inch with a maintained solution of a chloride of a heavy metal of the group consisting of zinc, copper, cadmium, mercury, iron, chromium, manganese, aluminum, nickel and cobalt.

4. The method of claim 1 wherein-isopropyl alcohol is employed. V V

5. The method of claim 1 wherein a solution of zinc chloride is employed. I

WALLACE ALEXANDER CRAIG. 

